This invention relates to the mounting of traction gear on the bottom of footwear, in particular, athletic footwear.
Conventional traction gear presently in use employ an attachment means consisting of screwing the traction gear into the mated receiving receptacle in the bottom of the footwear. Using this screw-type attachment method is especially laborious when one takes into account that a typical golf shoe, for instance, has eleven cleats; as a result, replacing the cleats on a pair of golf shoes entails unscrewing twenty-two cleats and screwing on twenty-two cleats, where each act of unscrewing or screwing entails several turns, typically two and one-half times, for each cleat.
An example of a typical prior-art cleat is in U.S. Pat. No. 4,723,366 (hereinafter the ""366 cleat), which patent is incorporated herein by reference. This patent describes a cleat which includes a metal stud infrastructure at the core of the cleat, the infrastructure having a vertical axis and two ends, a screw portion at a first end for engagement with a receptacle within a shoe, a ground end for tractive engagement with the ground, and a broad flange between the screw and head portions and extending radially outward from the vertical axis; a plastic skirt is molded directly upon the flange portion to form a unitary reinforced radial support member of the cleat. Installation of the ""366 cleat consists of screwing it into a mated receptacle in the bottom of athletic footwear.
Although some prior-art references show cleat-attachment systems that require less than a full turn, or they require a snap-on arrangement to lock the cleat in place, it appears none of these systems have found wide acceptance amongst users because of shortcomings in stability, ease-of-use, receptacle size and ease-of-manufacture. For instance, in U.S. Pat. No. 4,633,600 to Dassler, a cleat attachment system is disclosed in which a snap ring socket is utilized to affix a cleat to the bottom of a shoe.
In U.S. Pat. No. 3,267,593 to Turner, a cleat attachment system is disclosed wherein the top of the cleat spike has two extensions forming a rough T-shape out of the spike, where the spike is inserted into a mated receptacle having two grooves to receive the extensions. Upon complete insertion of the spike into a receptacle, the spike is turned until the extensions drop into receiving grooves at the top of the receptacle; a retaining ring is then slid onto the mid-section of the spike, this ring apparently preventing the spike from unseating the extensions from the grooves.
Similarly, in German Patent Application Nos. DE3134817A1 to Sportartikelfabrik Karl Uhl GmbH, and DE3423363A1 to Gebrxc3xcder Goldschmidt Baubeschlxc3xa4ge GmbH, another T-spike design is disclosed in which internal to the mated receptacle are ramping means for engaging and retaining the spike extensions. In the former, a rough interior surface catches the extensions, while in the latter, a sloping interior engages the extensions.
U.S. Pat. No. 4,492,047 to Arff, discloses another T-shape spike in which the skirt is deformed during insertion. Insertion of the spike causes the extensions to go up a ramp and then down a ramp, pulling the spike into the receptacle, and leaving the extensions in a holding area. The skirt is deformed so as to result in a pressure against the socket, the pressure apparently holding the spike from accidentally traveling back up the ramp towards removal.
In U.S. Pat. No. 4,035,934 to Hrivnak, another T-shape spike is disclosed in which the spike column has two indentations. During installation, two spring arms, each positioned perpendicular to the surface of the shoe and parallel to the spike, are pressed in during insertion of the spike, and spring back out to press against the indentations upon complete insertion. Removal of this spike is achieved with a U-shaped tool which slides into the spike receptacle and pushes in the spring arms, thus freeing the spike for removal.
A representative embodiment of the present invention includes a method of installing a removable cleat to the sole of a shoe. The method includes providing a cleat having (1) a ground-engaging structure for engaging the ground; and (2) an attachment structure for removably attaching the cleat to the footwear. The attachment structure has a vertical axis, a base to which the top of the ground-engaging member is attached, and a plurality of extensions attached to the base. A receptacle is provided for receiving and holding the cleat, the receptacle being mounted in the sole of a shoe. The receptacle has (1) a wall defining a cavity between a receptacle top and a receptacle bottom, wherein portions of the wall extend radially inward toward a central vertical axis of the receptacle so as to define: (i) a plurality of inclines within the cavity, and (ii) a plurality of protuberances within the cavity, each protuberance extending radially inward toward the vertical axis further than the compressible inclines; (2) a restraining ledge attached to the receptacle bottom and extending into the cavity so as to prevent downward movement of an installed cleat; and (3) an opening in the restraining ledge having at least three equidistantly spaced radially projecting lobes that extend radially outward from the central vertical axis of the receptacle. The cleat extensions are inserted through the receptacle opening into the receptacle cavity. Then, the extensions are engaged above the restraining ledges so that the cleat is securely attached to the receptacle so as to resist rotational movement of the cleat.
In a further embodiment, each cleat extension may have a radial end and an angled indentation located towards the radial end, and the act of engaging may include engaging each angled indentation with an incline. The plurality of cleat extensions may be equidistantly spaced. Also, the plurality of cleat extensions may lie in a plane perpendicular to the vertical axis of the attachment structure. The cleat may further include a skirt located between the top of the ground-engaging structure and the bottom of the attachment structure base, the skirt extending radially outward beyond the radial ends of the extensions so that when the cleat is attached to the receptacle, the skirt covers the opening in the restraining ledge.
The skirt may include a plurality of openings on the ground-engaging structure side of the skirt so that a cleat wrench may be inserted into the skirt openings to maneuver the cleat. Each incline may have a relatively gradual front ascent portion and a relatively steep back descent portion. Engaging the extensions may include securing each extension between an incline and a protuberance so as to resist rotational movement of the cleat.
Another representative embodiment includes a removable cleat for a shoe. The cleat includes a ground-engaging structure for engaging the ground; and an attachment structure for removably attaching the cleat to the footwear. The attachment structure has a vertical axis, a base to which the top of the ground-engaging member is attached, and a plurality of extensions projecting radially outward from the base. The extensions are adapted for insertion into a cleat receptacle in the shoe to engage a receptacle attachment structure within the receptacle, so that when the cleat is attached to the receptacle, each cleat extension will be securely engaged above a receptacle restraining ledge.
In a further such embodiment, the attachment structure engaged by the cleat extensions includes an incline and a protuberance for each cleat extension, arranged so that when the cleat is attached to the receptacle, each cleat extension is secured between an incline and a protuberance so as to resist rotational movement of the cleat. Each incline may include a relatively gradual front ascent portion and a relatively steep back descent portion. Each protuberance may extend radially inward toward the. vertical axis of the attachment structure further than the compressible incline. Each extension may have a radial end and an angled indentation located towards the radial end, the angled indentation being adapted to engage a corresponding incline when the cleat is attached to the receptacle.
The plurality of cleat extensions may be equidistantly spaced. The plurality of cleat extensions may lie in a plane perpendicular to the vertical axis of the attachment structure. The cleat may further include a skirt located between the top of the ground-engaging structure and the bottom of the attachment structure base, the skirt extending radially outward beyond the radial ends of the extensions so that when the cleat is attached to the receptacle, the skirt covers the receptacle.
The skirt may have a plurality of openings on the ground-engaging structure side of the skirt so that a cleat wrench may be inserted into the skirt openings to maneuver the cleat.